Molecular cloning of an immunoglobulin gene encoding the heavy chain of a monoclonal antibody specific for the pre-S2 antigen of hepatitis B virus

Abstract

We have cloned an immunoglobulin gene which encodes the heavy chain of a murine monoclonal antibody (mAb) (y2b, k) specific for the pre-S2 surface antigen of HBV from H8 hybridoma cell line. The genomic library, harbored in X EMBL3 and constructed from the H8 cells, was screened in parallel with the variable region of heavy chain-specific cDNA coding for the H8 mAb and the Ig heavy chain gene intron enhancer-specific oligonucleotide used as probes. One (X6-1) out of 200,000 plaques gave positive hybridization signal with both probes. Southern analysis of the positive clone revealed that a 6.6-kb Ec公R1 fragment carries a functionally rearranged heavy chain variable region (VH) gene and the Ig heavy chain gene intron enhancer. The nucleotide sequence analysis showed that the gene contains a functionally rearranged VH gene and the transcriptional elements required for B cell-specific expression. The Vh gene fused with human Cyl gene was expressed in murine myeloma cells, and directed the synthesis of the heavy chain mRNA,